Method for producing copper articles



United States Patent 3,163,528 1 METHQD Fflli PRGDUCHNG C(BPPER ARTECLES Robert E. Cech, Madiscn, Wis, assignor to General Electric Company, a eerporation of New York No Drawing. Filed Feb. 1, 11963, Ser. No. 255,671 3 Claims. (c1. 75-223 This invention relates to metal processing and more particularly to a process for producing coherent, copper bodies by the in situ reduction of copper chloride.

The manufacture or production of metal bodies often involves many problems and difficulties which while many times capable of being overcome, can result in excessively high manufacturing costs and in articles which are effectively compromise solutions of what was actually desired. The production of copper sheet, for example, from particulate or powdered copper presents difficulties in feeding the powder uniformly, due to bridging and the like. Additionally, the surfaces of each particle becomes more or less oxidized so that the final product may contain a higher oxide content than is acceptable.

It is a principal object of this invention to provide a process for producing coherent copper bodies by the in situ reduction of copper chloride.

Another object of this invention is to provide a process for producing coherent copper articles from particulate copper chloride which holds oxide contamination at minimum levels.

Broadly, the process of this invention involves providing a carbonaceous, organic body which has an interconnecting pore network, and then filling the pore network with particulate copper chloride. The organic body must be one which reacts in the presence of water vapor to form carbon monoxide and hydrogen, these two materials then reducing the copper chloride in situ. Continued heating completely removes the carbonaceous, organic material and leaves in its place a mat-like construction of copper fibers which can then be sintered to increase the strength thereof.

It was indicated previously that the present invention is one in which coherent copper bodies of various shapes can be produced more expeditiously and economically than has been possible in the past. The first element which is necessary to carrying out the present invention is a suitable carbonaceous, organic body which contains an interconnecting pore network. It is important that the pore network be interconnecting so that upon reduction of the copper chloride, a coherent or integral copper mass remains. In the absence of this type of continuity, reduction of the chloride would result only in the formation of copper powder and thereby obviate one of the more valuable advantages of this invention. Materials such as fibrous cellulosic materials, paper for example, constitute valuable substrate materials since they can be obtained in extremely long lengths and vari- Ous widths. Thus, by impregnating the pores of a paper sheet with copper chloride, the paper can be burned away and a copper sheet left in its place. For example, a suitable paper substrate can be continuously unreeled and impregnated with copper chloride by running it through a water suspension of particulate copper chloride. Upon completion of impregnation, the sheet can be run directly into a furnace containing a steam atmos phere and raised to a temperature resulting in reaction between the carbon of the paper and the steam to form carbon monoxide and hydrogen which in turn reduces the copper chloride. The heating is continued until all of the consumable material of the paper is gone so that essentially only a porous copper sheet remains.

Patented Dec. 29, 1964 This sheet can then be raised to a suitable sintering tempera ture to increase its strength and then cold rolled to consolidate the sponge-like sheet into a more dense form.

Considering a specific example of this invention, a sheet of fiiter paper was impregnated with cuprous chloride by filtering the liquid material through the paper and trapping the cuprous chloride in the interstices thereof. This paper was then placed in a furnace under a steam-hydrogen atmosphere and heated. The copper chloride was first reduced on the paper fiber surface by the volatile hydrocarbons in the cellulose. Continued heating caused the carbon in the fibers to react with the steam and produce hydrogen and carbon monoxide gas. This gas reduced more copper chloride on the copper surfaces so that the final structure was a mass of fine copper tubes which replaced the original paper fibers.

It will be appreciated that this invention is not limited to paper or cellulosic organic materials but contemplates any carbonaceous, organic material which will provide the necessary reduction of copper chloride in the presence of heat and steam.

Although the present invention has been described in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A method for producing a coherent body of metallic copper comprising, impregnating the pores of a cellulosic, organic body having an interconnecting pore network with particulate copper chloride, and heating the impregnated organic body in a furnace in the presence of water vapor to a temperature sufiicient to cause the carbon in the organic body to react with the water vapor and produce hydrogen and carbon monoxide and reduce the copper chloride to metallic copper.

2. A method for producing a coherent body of metallic copper comprising, impregnating a cellulosic fibrous, organic body having an interconnecting pore network with particulate copper chloride, heating the impregnated cellulosic fibrous body in a furnace in the presence of water vapor to a temperature sufiicient to cause the carbon in the fibrous body to react with the water vapor and produce hydrogen and carbon monoxide and reduce the copper chloride to metallic copper.

3. A method for producing sheet-like bodies of copper comprising, impregnating a fibrous, sheet-like body of cellulosic material with particulate cuprous chloride, heating the sheet-like body in a furnace in the presence of water vapor to a temperature sufficient to cause the carbon in the cellulosic body to reduce the copper chloride to metallic copper, and form a copper sheet and sintering the reduced copper to increase the strength of the copper sheet.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain June 10, 1953 

1. A METHOD FOR PRODUCING A COHERENT BODY OF METALLIC COPPER COMPRISING, IMPREGNATING THE PORES OF A CELLULOSIC, ORGANIC BODY HAVING AN INTERCONNECTING PORE NETWORK WITH PARTICULATE COPPER CHLORIDE, AND HEATING THE IMPREGNATED ORGANIC BODY IN A FURNACE IN THE PRESENCE OF WATER VAPOR TO A TEMPERATURE SUFFICIENT TO CAUSE THE CARBON IN THE ORGANIC BODY TO REACT WITH THE WATER VAPOR AND PRODUCE HYDROGEN AND CARBON MONOXIDE AND REDUCE THE COPPER CHLORIDE TO METALLIC COPPER. 